using System;
using System.Text.RegularExpressions;
using System.Configuration;
using Doo.HttpModule.URLRewriter.Config;

namespace Doo.HttpModule.URLRewriter
{
    /// <summary>
    /// Provides a rewriting HttpModule.
    /// </summary>
    public class ModuleRewriter : BaseModuleRewriter
    {
        /// <summary>
        /// This method is called during the module's BeginRequest event.
        /// </summary>
        /// <param name="requestedRawUrl">The RawUrl being requested (includes path and querystring).</param>
        /// <param name="app">The HttpApplication instance.</param>
        protected override void Rewrite(string requestedPath, System.Web.HttpApplication app)
        {
            // log information to the Trace object.
            //app.Context.Trace.Write("ModuleRewriter", "Entering ModuleRewriter");

            // get the configuration rules
            RewriterRuleCollection rules = RewriterConfiguration.GetConfig().Rules;
            
            // iterate through each rule...
            for (int i = 0; i < rules.Count; i++)
            {
                // get the pattern to look for, and Resolve the Url (convert ~ into the appropriate directory)
                string lookFor = "^" + RewriterUtils.ResolveUrl(app.Context.Request.ApplicationPath, rules[i].LookFor) + "$";

                // Create a regex (note that IgnoreCase is set...)
                Regex re = new Regex(lookFor, RegexOptions.IgnoreCase);

                Match match = re.Match(requestedPath);
                // See if a match is found
                if (match.Success)
                {
                    // match found - do any replacement needed
                    string sendToUrl = RewriterUtils.ResolveUrl(app.Context.Request.ApplicationPath, re.Replace(requestedPath, rules[i].SendTo));

                    //See if the rule need save matches
                    if (rules[i].SaveMatch)
                    {
                        System.Collections.Specialized.NameValueCollection nvc = new System.Collections.Specialized.NameValueCollection();
                        foreach (string key in re.GetGroupNames())
                        {
                            nvc.Add(key, match.Groups[key].Value);
                        }
                        app.Context.Items[Doo.Config.DooKey.RewriterMatch] = nvc;
                    }

                    // log rewriting information to the Trace object
                    //app.Context.Trace.Write("ModuleRewriter", "Rewriting URL to " + sendToUrl);

                    // Rewrite the URL
                    RewriterUtils.RewriteUrl(app.Context, sendToUrl);
                    break;		// exit the for loop
                }
            }

            // Log information to the Trace object
            //app.Context.Trace.Write("ModuleRewriter", "Exiting ModuleRewriter");
        }
    }
}
